1. Field of the Invention
The present invention relates to a method of making metal I-beams of the type employed in building construction and the associated I-beam and, more specifically, it relates to improved hot rolled metal I-beams which resist the formation of undesired waves in the I-beam web and the method of making the same.
2. Description of the Prior Art
It has long been known to employ various types of metal beams, such as steel I-beams, in building construction of various types. Such beams have a web and a pair of flanges in opposite edges of the web such that the beams may be employed individually or in an assembly of such beams so as to safely support substantial static loads thereon.
It has been known to establish such beams by welding the flanges to the web. It has also been known to form such beams by hot rolling from a billet.
One of the problems which has been encountered with respect to hot roll forming of I-beams has resulted from the bulk distribution causing the web temperature and the flange temperature to be sufficiently different that the web cools faster than the flange thereby resulting in undesirable waves being created in the web due to the differential cooling rate. This temperature differential can, in some instances, equal about 250.degree. F.
U.S. Pat. No. 4,251,973 discloses an I-beam welded to flanges wherein an effort to cure the problem of web waviness due to temperature differential is disclosed. It employs a plurality of hollow corrugations formed within the web extending in a direction generally perpendicular to the longitudinal extent of the I-beam. See, also, German Patent 46414.
It has also been known to suggest providing open trusses for building construction wherein elongated truss ribs are initially formed within the web and are subsequently severed from major portions of the web and deformed to create the expanded open web truss construction. See U.S. Pat. Nos. 1,927,442 and 3,962,763.
U.S. Pat. No. 3,199,174 discloses securing a series of flat strips to the web to resist undesired web buckling "at the manufacture of the beam" and to strengthen the web against buckling caused by external forces.
It has also been known to provide a truss with a plurality of indentations in the web separated by elongated bars.
U.S. Pat. No. 2,263,272 discloses the manufacture of a steel I-beam by welding a web plate to a pair of T-sections.
U.S. Pat. No. 4,129,974 discloses an I-beam having a restraining structure in the form of a local reinforcing member which is generally channel-shaped and secured to the flanges and web at a particular longitudinal position. See, also, U.S. Pat. No. 2,392,674.
Reinforcement of a leading end of a pile member through the use of one or more weld beads is disclosed in U.S. Pat. No. 3,810,363.
In spite of the foregoing disclosures, there remains a real and substantial need for a method of making a metal I-beam by hot rolling without the presence of undesired waves in the web portion and the resultant product, as well as a building construction and other structural products employing one or more such I-beams in a load bearing manner.